Tension-releasing mechanism for sewing machines



Feb. 10, 1931. .1. R. MOFFATT ETAL TENSION RELEASING MECHANISM FOR SEWING MACHINES 2 Sheets-Sheet 1 Original Filed June 4, 1926 Patented Feb. 10, 1931 .UN ITEDiSTATEfi PATENT. F E, j

.mivrnsni Mamie, orcnroaeo, Ann nAnrri s; KELSO, or ROCKFORD, ILLINOIS, As-

sIGNons'ro UNION SPECIAL Macrame ooMrenY, or-cr rcneo, ntmois, A 003- PoReTIoN or I LInoIs a rniisronrnntnnsme'MncnAnIsMiron snwi'neivihcmnns' Original application 'filed Jnne 4,"1 92G," Seria1"No. 113,714. :Iiivikied and this application filed august 9, 1928. Serial No. 298.514. i 1 Z I The invention relates to new and useful :improvements in tensioin releaslng mecha- .ticularly to a tension releasing mechanism 5 for sewing machines having a series of stitchcing threads. v i v e I An object of the invention is to provide a machine having aseries of stitching threads with tension discs-for each: thread which are 10,mounted one ab ve another, and in sub;

stantially the same vertical plane as the. p v e I cross thread, and there lsa tGllSlOIL for each thread guidesassociated therewith, so that the threads pass .in substantially the same :plane from the guides receiving the thread from the supply to the operating parts of the machine. A further object of the invention is to providea machine of the above type with means for lifting the .presser foot and for simultaneouslyreleasing all of the tensions wherein the tension releasing. device for each pair of tens on discs 1s below the dlsc with Wl11Cl1 it is associated.

A still further object the invention is to V provide a tension releasing mechanism of the above type whereln the tension discs aremounted onsupporting posts and held at a fixed distance from the supporting bracket for the posts so that the tension releasing plate may slide freely on said post-s between the tension discs and the supporting bracket. These and otherobjects willin part be obvious and will in part be hereinafter more fully disclosed.

In the drawin s I armwhichreleasesqand lifts the tension releasing plate. nismsforsewing machinesjand more pari Fig. 5 is a sectional view on the line 5'5 of Fig. 2. i

.Fig. 6 is a sectional view on'the line 66 of Fig.1.

; Theinvention is directed to an arrangement of the tensions. for a sewing machine and the releasing mechanisms therefor. I "The, sewing machine is provided with a plurality of needl-ethreads, a looperthread, and a of these threads. .The tension consists of" a shoulderonthe post. In the present an bodiment of't'lie inventionQ-the posts are all arrangedv inaverticalplane and the tension discs are located one above another. vThe threads are led through suitable, guideeyes from the supply to. these tension discs and thence to otherguides and. to the needles, loo e r,and cross thread laying mechanism.

1 ractically all of the'thread guides for the needle threads'and the cross thread are 10-] cated in the same plane as the tension discs. This enables the threads to run very freely as the turningof. thefithread about sharp angles has'been avoided. ,-Mounted on the bracket supporting the-posts carrying the tension discs is a plate which is preferably arranged. to. slide verticallyonthe posts.

Said plate is common to all of the posts, and means is provided whereby when the presser foot is raised from thematerial, the plate is moved 'endwise in an upward direction. The plate carries an arm for each pair of tension discs and this arm has its upper edge wedgeshaped and the armis so disposed that when the plate is raised the wedge-shaped portion of the arm will pass between the tension discs and separate the same.

Referring more in'detail to the drawings,

the invention isshown as appliedto a sewing machine having a standard 1 on which is mounted an overhanging arm 2. The machine is provided with a work supporting arm 3. The machine is shown more in detail in the parent application, Serial No. 113,714, filed June 4, 1926, of which the present application is a division. It is not thought necessary to describe in detail the work supporting arm or the parts contained thereon, or the means for actuating the same. Mounted in the overhanging arm is a needle bar 4 carrying three needles indicated at 5 in the drawings.

Associated with the needles is a cover thread laying mechanism including a thread guide 6 and a hook 7. There is a thread for each needle, a thread for the looper which cooperates with the three needles, and a thread for the cross thread laying mechanism. The needle threads are indicated at mm, a. The cross thread is indicated at c, and the looper thread is indicated at Z. These threads pass through guide eyes in a bar 8 attached to the standard of the machine. Mounted on the standard of the machine is a bracket 9. This bracket is secured to the standard by suitable screws and is provided with a vertical portion 10 between the points of attachment.

Attached to this vertical portion of the bracket is a support 11 for the tensions. This support extends in a vertical direction and is provided with side members 12 and 13, as shown in Fig. 5 of the drawings. The

0 side member 12 is formed with a series of thread guides 14, one for each thread, and the member 13 is provided with a series of similar thread guides 15. Mounted on this support are five posts, each of which is indicated at 16. The posthas a threaded connection to the support and each post has an integral collar 17 which is of greater diameter than the post. There are a pair of tension discs 18 and 19 on each post. A spring 20 on each post normally forces the tension disc 19 against the tension disc 18 and the tension discs against the shoulder formed by the collar at the base of the post.

A nut 21 is provided for varying the tension of the spring. These tensiondiscs are all arranged one above another in a vertical line and in a vertical plane. The threads, after leaving the thread guides 14 pass through the tension discs, and thence through the thread guides 15. From this point the three needle threads are led to a thread guide 22 which is stationary, thence to a thread guide 23 carried by the needle bar and to the needles. The cross thread passes through a thread guide 24 and thence to the cross threa d laying device. The looper thread passes down alongside the standard and into the arm and to the looper. As clearly shown in Fig. 1 of the drawings, the guides in the support for the threads are located a slight distance beneath the tensions and the threads leaving the thread guides 14 pass in an upward direction over the post supporting the tension disc and thence in a downward direct-ion to the thread guide 15. This insures that the thread shall remain between the tension discs when the grip of the tension discs is released therefrom.

Mounted for vertical movement on the support for the tension posts is a tension releasing plate 25. This tension releasing plate, as shown in Fig. 3, is provided with elongated slots 26. These slots engage over the posts and the collars at the base of the posts. The plate is of less thickness than the thickness of the collar, and, therefore, the plate is free to slide vertically on the posts in rear of the tension discs. Said plate is held to the support by screws 25a, 25a. This releasing plate 25 is provided with a series of arms 27, one arm for each pair of tension discs. The arms lie beneath the tension discs with which they are associated. The upper edge of each arm is beveled so as to "form a wedge-shaped edge. hen the plate" 25 is raised the wedge-shaped edge of the arm will pass between the tension discs with which it is associated and separate the tension discs. Thus it is that the tension is re leased from the threads. is lowered,then the arm is moved from between the tension discs and the tensions are restored to their normal grip on the threads. The tension releasing plate is also provided with an arm 28 which is bent at right an- 7 gles to the plane of the plate and extends through a suitable opening 29 in the support 11. Mounted on the support 11 is a bracket which houses a spring 30. This spring bears on the arm 28 and normally presses the plate downward. The lower end of the opening 29 serves as a stop for limitingthe down ward movement of this tension releasing plate.

The presser bar is raised from the material by means of a lever 31. This lever may be connected through a suitable flexible means 32 with either a treadle or knee shift. The lever is attached to a shaft 33 which is provided with suitable means at the forward end of the machine for raising the presser toot. Mounted on this shaft 38 is an arm 3%. The arm 34: is provided with a slot 35 through which a screw passes for securing said arm in different set positions tothe lever 31. This arm projects laterally as indicated at 36 in Fig. 4 of the drawings, and the laterally projecting portion of the arm lies directly underneath the arm 28 which is attached to the tension releasing plate.

When the lever 31 is depressed this arm 36 will engage the arm 28 and lift the tension releasing plate which will cause the tension discs to be separated and the tension on all threads to be released. A spring 37 turns When the plate ont ofoontactwhen theprcsser foot is lowver.cd onto the material.

the leverto a position where the armsare From-the above it will be: apparent that an arrangement ofthread guides andtens-ion discs have been provided wherein the threads are comparatively free from sharp turns so that they-flare free running .d-uring the operationlof the machine, These tension discs are all arranged-one above another and are. re lea-sed'by aoommon plate moving in a verl Inasmuch as the arms on the tical direction. 7 tension releasing plate are beneath the ten sion discs gravity will aid in the moving of the arms away from the tension discs. Fur

thermore, by placing thetensionposts in a horizontalpos'ition any dirt or lint accumulating between the tension discs will drop therefrom when said. discs are separated. The tension releasing plate operates simule taneously on'all the tension discs and this insures that all tenslons Wlll. be released when the presser foot is raised. While all of the tensions are shown as disposed in vertical plane one'above the other,'it will be obvious from certain aspects of the invention that some or all of the tensions may be otherw se disposed. The essential feature of this part of the invention consists in the arranging'of a plurahty of tensions in a vertical plane one above the other and providing a tension re-= leaslng plate common to the tension 'CllSCS.

with means for simultaneously separating the tension discs when said plate is raised.

The guides 22 for the three needle threads are formed in a laterally extending portion of the arm 38. This arm 38 is adjustably secured in a sleeve 39 mounted onthe end of an arm 40 which, in turn, is adjustably se;

cured in a sleeve ll carried by thebraclret 42. The arm 40 1s horizontal and capable of endwise ad]ustment. The arm .58 is also capable of vertical and oscillatingadjustment in the sleeve at the end of the arm 40.

Through these adjustments the thread guides I 22 maybe moved nearer to and farther trom tionary thread guides22. V

It will be obvious that minor changes in the details of construction may be made without departing from the spirit of the invention as set' forth in the appended claims.

Having fully described our invent-ion, what we claim as new and desire to secure by LettersPatent, is r 1; A sewing machine including in com bination a needle bar, a plurality of needles r carried thereby, an arm secured to the needle bar and havingthread guides for the needle threads, a support, .a series of tension-discs i mounted 1011 said support one for each needle thread, said discs being located one above another, astationary arm located between the m tension discs and-the arm on the needle bar and having ,a series of thread guides for the needlejthreads, means for supporting said" statlonary arm so that; the same, may be raised and lowered and means for: supporting saidjarm so thatt'he same may be shifted toward or from the needle-bar V l r 2.- A :sewingmacohine including in com xbination a needle bar, a plurality of needles carried thereby, an arm secured to the needle 7 bar and having thread guides for the needle threads, a support, a series .of tension discs mounted onsaid support one for each needle thread, saiddisos beinglocated one aboveanother, a stationary arm located between; the

tension discs and the arm on the needle bar and-having a seriesof thread guides for the needle threads, means forsupporting said stationary arm. so thatthe same'may be raised and lowered or shifted toward or from the needle bar, said last-namedarm having a lat- ;era-lly projecting; portion' for the thread guides, said means for supporting said arm includingva'sleeve in which said arm' is cillating-movement. a

3. A sewing machine ncluding in comblnatlon a: support, a series. of-posts mounted on said support one above the other, each post mountedfor endwise' movement and also os- .havinga'shoulder thereon spaced from said support, a pair oftensiondiscs on eachpost normally resting against saidzshoulder, tension means for presslngfthe d sosagainst the shoulder, thread guides for guiding anginde pendent threadoto each pair ,of tension discs, a plate having an opening therethrough adapted to receive said posts and slidable on the posts between the support and the shoulder, anlarm on said plate for ea'ch pair of tension. discs, said arm being. located between the tension discs and having a wedge-shaped upper edge portion adapted topa'ss between the discs and separate the ssmefwhen the plate is raised, and means under the control of the operator for raising said plate.

4:. A sewing machine including in combination a support' a series of posts mounted Onsaid support one above the other, each post having a shoulder thereon spaced from said support, a pair of tension discs on each post normally resting against said shoulder, tensionmeans for pressing the discs against the shoulder, thread guides for guiding an independent thread to eachpair of tension dics, a plate having an opening therethrough adapted to recelve sa d posts and slidable on r the posts between the support and the shoulder, an arm-on said 'plate for each pair of tension discs, said arm being located between the tension discs and having a wedge-shaped upper edge portion adapted to pass .between the discs and separate the same when the plate is raised, and means under the control of the operator for raising said plate, said means for raising the tension releasing plate including devices for raising the presser foot of the sewing machine, said means for-raising the tension releasing plate being adjustable so as to vary the extent of movement imparted to said tension releasing plate.

5. A sewing machine including in combination an overhanging'arm, a bracket carried by said arm, a support extending in a vertical direction attached to said bracket, a series of posts mounted on said support one above another, each post havinga shoulder adjacent the support, a pair of tension discs on each post, a spring for pressing said tension discs against the shoulder, means for varying the tension onsaid discs. said support carrying thread guides for guiding thread between the tension discs. said thread guides being located in a line beneath the posts with which they are associated. a plate carried on said support for vertical movement, said plate having an arm associated with each pair of discs located beneath the discs and provided with a wedge-shaped portion at its upper edge adapted to passbetween the discs when the plate is raised for separating the discs, and means for raising and lowering said tension releasing plate.

6. A sewing machine including in combination an overhanging arm, a bracket carried by said arm, a support extending in a vertical direction attached to said bracket, a series of posts mounted on said support one above another. each post having a shoulder adjacent the support, a pair of tension discs on each post, a spring for pressing said tension discs against the shoulder, means for varying the tension on said discs. said support carrying thread guides for guiding thread between the tension discs. said thread guides being located in a line beneath the posts with which they are associated. a plate carried on said support for vertical. movement, said plate having an arm associated with each pair of discs located beneath the discs and provided with a wedge'shaped portion at its upper edge adapted to pass between the discs when the plate is raised for separating the discs, and means for raising and lowering said tension releasing plate, said last-named means including devices for raising the presser foot of the machine when the tensions are released, and adjustable devices for raising and lowering the tension releasing plate so that the extent oi movement imparted thereto may be varied.

7. A sewing machine including in combination a plurality of tensions arranged one above another, each of said tensions having a pair of tension discs, a support upon which JAMES R. MOFFATT. 

